2f Acids, Alkalis and titrations

Question 1

What is the formula for hydrochloric acid?

Answer 1

HCl

Question 2

What is the formula for Sulphuric acid?

Answer 2

H2SO4

Question 3

What is the formula for nitric acid?

Answer 3

HNO3

Question 4

What is the formula for Phosphoric acid?

Answer 4

H3PO4

Question 5

What does basicity mean?

Answer 5

How many hydrogen ions can be replaced in an acid molecule

Question 6

What does Methyl orange measure?

Answer 6

It can only show whether a substance is acidic or alkaline
acidic - red
alkaline/neutral - yellow

Question 7

What does Phenolphthalein measure?

Answer 7

It can only show whether a substance is alkaline or not

acidic/neutral - colourless
alkaline - pink

Question 8

What does Universal Indicator measure?

Answer 8

It can measure whether something is an acid or alkaline. And it can tell you how strong and acid or alkali is

Question 9

Why can acids be proton donator?

Answer 9

Because a hydrogen ion only has a proton subatomic particle.

Hydrogen atom - p - 1
e - 1
n - 0
Hydrogen ion - p - 1
e - 0
n - 0

Question 10

What is the basicity of hydrochloric acid?

Answer 10

Monobasic (one H+)

Question 11

What is the basicity of sulphuric acid?

Answer 11

Monobasic (One H+)

Question 12

What is the basicity of Nitric acid?

Answer 12

Dibasic (Two H+)

Question 13

What is the basicity of Phosphoric acid?

Answer 13

Tribasic (Three H+)

Question 14

What is basic?

Answer 14

The term used to describe oxides and hydroxides of metals (base). Bases can be described as proton acceptors (in other words they accept the H+ ion released by acids). Some bases are soluble and will dissolve in water. A soluble base is called an alkali.

Question 15

What is the formula of Sodium Hydroxide?

Answer 15

NaOH

Question 16

What is the formula of Potassium Hydroxide?

Answer 16

KOH

Question 17

What is the formula of Calcium Hydroxide?

Answer 17

Ca(OH)₂

Ca2+ OH-
Ca(OH)2

Question 18

What is a neutralisation reaction?

Answer 18

When an acid is added to an alkali a neutralisation reaction occurs

H+(aq) + OH(aq) -> H2O(l)

Question 19

What is a chemical salt?

Answer 19

A chemical salt is a substance formed when one or more hydrogen atoms in an acid is replaced by a metal

Question 20

What is the salt name for hydrochloric acid?

Answer 20

chloride (Cl-)

Question 21

What is the salt name for nitric acid?

Answer 21

nitrate (NO3-)

Question 22

What is the salt name for sulfuric acid?

Answer 22

sulfate (SO42-)

Question 23

What is the salt name for phosphoric acid?

Answer 23

phosphate (PO43-)

Question 24

What chloride salts are soluble?

Answer 24

All Soluble (except silver or lead chloride)

Question 25

What sulphate salts are soluble?

Answer 25

All soluble (except calcium, barium or lead sulphate)

Question 26

What sulphate salts are nitrates?

Answer 26

All soluble

Question 27

What sulphate salts are carbonates?

Answer 27

Insoluble (except sodium or potassium carbonate)

Question 28

What is an acid?

Answer 28

A substance that contains replaceable hydrogen atoms with form H+ (aq) ions when the acid is dissolved in water. It has a pH less than 7.

Question 29

What is a base?

Answer 29

Substance that neutralises an acid to produce a salt + water. These are usually solid metal oxides or hydroxides

Question 30

What is an alkali?

Answer 30

A base that is soluble in water and produces OH-(aq) ions. It has a pH greater than 7.

Question 31

What is a salt?

Answer 31

Compound made from the reaction of an acid and a base

Question 32

How to do the titration method?

Answer 32

1) A burette which has first been rinsed with distilled water is filled with hydrochloric acid using a funnel; remove the funnel afterwards 2) Measure out exactly 25.00cm3 of dilute sodium hydroxide and add it to a conical flask. An indicator is added to the solution being analysed. This will change colour when the reaction is complete. We are using methyl orange or Phenolphthalein indicator. 3) Take the initial reading of the burette and record it in your results table. Add the acid from the burette to the contents of the flask, while the flask is swirled constantly. Near the end point the solution is added drop by drop. 4) At the end point from the indicator changes colour. Record the final volume of the acid and record it in your results table. Work out the total volume of the acid added. This is the titre. Wash out the conical flask with distilled water and repeat the titration until 2 of the readings agree within 0.10cm3.

Question 33

How to obtain pure dry chemical salt using titration method?

Answer 33

Once the exact volume of acid is needed to neutralise the fixed volume of alkali is found: 1) Repeat the titration using exact volumes from experiment and NO INDICATOR. 2) Pour the salt solution into an evaporating basin and gently heat (To remove water) 3) Once the crystallization Point is reached (solid formed when solution placed on a cold glass rod), stop heating 4) Leave in a warm oven to dry